Studies on the Cold-hardness of the Rice Stem Bore Chilo suppressalis (Walker)
WANG Xiao-qi; LI Zhao-fei; FENG Hong-qiang, et al.(Department of Plant Protection, Shenyang Agricultural University, Shenyang Liaoning, 110161)
The percent death of over-wintering larva of the rice stem borer Chilo suppressalis (Walker) at constant low temperatures -15 ℃ (30 days), -20 ℃ (4, 6, 8, 10 days), -23 ℃ (4 days), -25 ℃ (4 days), respectively were 3.33%, 6.67%, 13.33%, 23.33%, 26.67%, 30%, 56.67%. During the over-wintering period, the percent death directly caused by natural low temperature were investigated in field at pre-winter, mid-winter and post-winter,i.e., 0, 4.85%, 9.96% respectively. The over-wintering larva could tolerate some strong lower temperatures: -28℃(90min), -30 ℃ (30min), -32 ℃ (10min). The over-wintering larva had different cold-hardness at different time.Before mid-March, the super-cooling point (SCP) showed rising trend, after mid-March it began to decrease.The over-wintering larva collected from different latitudes also showed some differences in cold-hardness. The SCP was rising with the latitudes increasing. It is concluded that the over-wintering larva were survival in cold winter by tolerating and avoiding strategy.
【CateGory Index】： S435.112.1